Squashed 'external/ViennaMini/' changes from fa660d6..b08c1c1

b08c1c1 trigate example: same simulation setup as ViennaFVM - results are similar
470979e simulator class: debugged permittivity handling

git-subtree-dir: external/ViennaMini
git-subtree-split: b08c1c1b6e94cd98306066adfb7812b6543e82be
Merge commit '026b8ed615ded467d553e9049694268cb170ab35'
Squashed 'external/ViennaFVM/' changes from c7c4652..b554b40

b554b40 improved mosfet_3d default setup + adjusted debug messages of pde_solver
9d610e5 mosfet(3d) examples: using viennagrid's scaling + mosfet3d: fallback to normal simulation setup
e35558b mosfet example: added initial/boundary vtk writer methods

git-subtree-dir: external/ViennaFVM
git-subtree-split: b554b40f1b53eb474d51432d9cccea9a7f750f02
Merge commit 'a723bbb094ab848e7bbd37bcadf58c70a9723b19'
Squashed 'external/ViennaGrid/' changes from 6707c50..961818d

961818d Using static const instead of enum for compile-time values
a2fbf6c re-added numeric, re-added geometry
bb47165 renamed element_segment_info -> segment_element_info
c0b8647 const correctness in element_segment_info
b10f195 added create_unique_vertex with automatic tolerance
9f5c148 operator= and copy constructor isn't buggy anymore :)

git-subtree-dir: external/ViennaGrid
git-subtree-split: 961818d325a9b1f89d642a4273a2bb3a86e78d0a
Merge commit 'e12641e0bb2c1bc24df2dade209edb2854ae1cf2'